1. Field
The present disclosure relates generally to battery systems and, in particular, to battery systems with multiple battery cells. Still more particularly, the present disclosure relates to a battery system in which battery cells are removably bonded to the housing of the battery.
2. Background
In the aerospace industry, batteries are used for a number of different purposes. For example, batteries may be used as backup in case a primary power generator fails to operate as desired. In other examples, batteries are used to provide power when more power is needed than can be generated by the primary power generator.
For example, spacecraft often carry onboard power generation systems that include power generators and batteries. These spacecraft may include, for example, satellites. A satellite orbiting the earth may use a power generator in the form of solar cells. The solar cells generate power from exposure to sunlight. This power is used by various devices in the satellite. These devices may include, for example, communications systems, switches, computers, and other suitable types of devices.
The satellite, however, may not always have sufficient sunlight exposure to generate the amount of power needed by the satellite. Batteries are used in the satellite to supply power in these situations. When sufficient sunlight is present, the solar cells are used to recharge the battery, as well as provide power to other devices on the satellite.
Typically, a battery is comprised of battery cells. Each battery cell generates electricity and provides power to different devices in the satellite. These battery cells are arranged in series or parallel to form the battery.
A battery for use in a spacecraft is designed to provide proper support for the battery cells. This support is designed to support the battery cells during loadings and/or vibrations that may be encountered. These loadings and/or vibrations may be encountered during testing, transportation, and/or launching of the spacecraft. The loadings also may occur from internal pressures from within the battery cells during operation of the battery.
Additionally, heat is another consideration taken into account when designing a battery. When a battery is used, chemical reactions occur to generate the electricity to provide power to the different devices. Chemical reactions also occur during recharging of the batteries.
These chemical reactions result in a production of heat. As a result, a battery is designed such that the heat produced does not reduce the ability of the battery to generate power.
For example, a battery may be designed such that heat generated by the battery cells is conducted away to a heat sink. The conduction of heat reduces the heating of the battery cells above desired temperatures. These temperatures are selected as ones that avoid reducing the life of the battery cells in the battery.
In designing batteries for use in spacecraft, such as satellites, weight and complexity are examples of other design considerations. Reducing the weight of the satellite is an important design consideration. For example, weight limitations are often present based on the launch vehicle that may be used to place the satellite into orbit. If the satellite weighs too much, a more expensive launch vehicle may be needed. In some cases, the weight of the satellite may increase the difficulty in placing the satellite into orbit.
In many conventional systems, replacing battery cells may require disassembly of the entire battery. The different rods may be disassembled, the battery cells replaced, and the rods reassembled. The rods used to bind the battery cells together are large in number and require time to secure to each other to secure the battery cells. This type of design for the battery increases the amount of time needed to rework a battery. Furthermore, the rods may lose pre-load binding strength to hold the battery cells together. This loss may occur from thermal cycling, creep, and/or vibration. As a result, over time, the battery cells may not be held together as tightly as desired.
Therefore, it would be advantageous to have a method and apparatus which takes into account one or more of the issues discussed above, as well as other possible issues.